Conventionally, JP-A-2004-144395 discloses an evaporator unit that includes heat exchangers on the upstream and downstream air sides, and adapted to equalize the temperature distribution of air blown therefrom.
In the related art, refrigerant flowing through the evaporator unit is allowed to flow through the heat exchanger on the downstream air side and the heat exchanger on the upstream air side in series in that order without being branched and joined. Thus, as the refrigerant flows from the heat exchanger on the downstream air side toward the heat exchanger on the upstream air side, the evaporation of the refrigerant proceeds to increase the dryness of the refrigerant.
Generally, the dryness of refrigerant with a high heat exchange property is in a range between 0.6 and 0.9.
Since the dryness of refrigerant is increased as the refrigerant flows from the heat exchanger on the downstream air side to the heat exchanger on the upstream air side in the related art, the entire evaporator unit including a combination of the two heat exchangers on the upstream and downstream air sides has only one part thereof at which the dryness of refrigerant is in a range between 0.6 and 0.9.